Touch contamination in medical-care environments has been identified as a frequent contributor to medical complications including vascular-access-associated infections and is now considered a leading compromiser of patient safety.
Hospital-acquired bloodstream infections are estimated to cause thousands of deaths a year and billions in lost revenues; many of these are related to indwelling vascular access devices, including intravenous (IV) catheters. Non-sterile contact of a sterile surface of a medical device with a non-sterile surface can contaminate a medical device. This can have deadly results when dealing with intravascular fluid connectors since contamination through an intravascular line can bypass the skin barriers and be directly transmitted into the bloodstream, and throughout the body, to key organs such as the brain or heart, and/or could lead to widespread sepsis, shock and death.
Care must be made when connecting intravenous devices as even minute contamination of critical connector surfaces could introduce bacteria directly into the fluid path entering the bloodstream. Contamination risks frequently are thought to occur at the site of insertion of an intravascular line; however, it is applicant's observation that a frequently overlooked factor in contamination is the subsequent connections and in particular the insertion of the male “Luer” tip into the compatible female “Luer” connector.
Luer connections have been identified as sources for infection. Tragically, little has been done to successfully deal with producing a better connector that helps to reduce infection and is acceptable to the medical marketplace for widespread use. A simple system to protect Luer connectors that assures universal connectivity with standard and non-standard female Luer-like connectors, while also providing widespread protection against contact contamination, does not currently exist.
Contact of a sterile surface of a medical device with a non-sterile surface is a common mode of hazardous contamination. This contamination can have deadly results when dealing with intravascular fluid connectors as contamination through an intravascular line bypasses the skin barriers and directly transmits the contamination into the bloodstream and throughout the body to key organs such as the brain or heart, and/or could lead to widespread sepsis, shock and death.
Luer connectors are ubiquitous throughout the healthcare industry and frequently are used to provide connections to intravascular access. Luer connectors refer to large bore and small bore Luer connectors, not just any device with a 6% Luer angle. In the present invention, “Luer connectors” preferably refers to small bore Luer connectors. Luer devices are standard for intravenous access. Intravenous catheters have a female lock Luer hub on a proximal end that receives another medical device with male Luer connector on the distal end. These male Luer connectors are frequently Luer lock connectors with internally threaded collars, which help secure the connection between the male and female Luer connectors.
Luer connectors originated in late 1800s when Wolfgang Luer invented a two piece syringe. The Luer connector that followed comprised a 6% taper. Luer locks were a later advance that assisted with securing with threaded connections. The earlier Luer and Luer-lock connectors were made of steel and glass and standards existed as early as the 1950s; only in the early 1990s was a standard developed for plastic components with the ANSI standard. Shortly thereafter, a more comprehensive ISO standard was developed that has become the guiding document for the medical industry.
This ISO standard (ISO 594-1:1986 and 594-2:1998) insures the universal compatibility of multiple devices; however, the international dimensional standards also provide an obstacle to modifying Luer devices to prevent contact contamination. Female Luer connector hubs are recognized as the receiving end for male Luer connectors. It would be inconvenient and at times extremely dangerous to have non-compatible connectors. For example, when wanting to give resuscitation drugs in an ambulance, if the paramedic's intravenous (IV) tubing did not match the IV catheter, this would be dangerous. Even if an adapter were available in a separate package, time lost could lead to blood spills and biohazard risks while locating and opening the separate packaging of the other connector, as well as the delay in resuscitation medication delivery and distraction and confusion of the critical event.
While there has been a move to specialize connectors to reduce misconnection issues, it is generally accepted that the Luer standard is likely to remain the primary standard for intravascular access. While new standards may be developed for intrathecal administration or enteral administration, the current Luer standards are likely to persist.
Upstream from IV catheters, intravenous extension connectors, access ports, and fluid administrations sets connect necessary accessory tubing with the same convention of having female Luer-like receiving ports. For IV administration sets, frequently the most proximal portion contains an IV spike that inserts into the fluid origination source of a bag of IV fluid.
Inline adapters are attached with an open ended female IV catheter hub that accepts a standard male Luer adapter. For example, there are many port access devices that are attached to IV catheter hubs for intermittent access. Port access devices can also be located more proximally up the chain of extension tubing. The IV catheter ports can provide an end adapter that allows the proximal IV tubing to be removed from a distal IV catheter.
Originally these port and port caps allowed for needle insertion and access for the intermittent or continuous administration of IV medications and fluids. These ports required cleaning with disinfectants such as an alcohol swab prior to the insertion of a needle through the pierceable endwall (to reduce the risks of directly inoculating microorganisms on the outer surface into the inner lumen). More recently, these IV catheter ports have been adapted for needleless connection directly to syringes, tubing etc. with male Luer connector tips. In some cases, the design of these needleless connectors has led to increased risk of intravascular contamination, which will be discussed below.
Care must be made when connecting with and accessing intravenous devices because even minute contamination of any of these surfaces could introduce bacteria directly into the fluid path entering the bloodstream. Contamination risks frequently are thought to occur at the site of insertion of an intravascular line. However, it is applicant's observation that a frequently overlooked factor in contamination is the subsequent connections and in particular the insertion of the male Luer tip into the female connector.
In general, contamination is at a high risk of occurring when a male Luer device is inserted into the female Luer to assemble a closed intravenous fluid delivery system and also when the closed tubing system is accessed; for example, when a port, such as female Luer or female Luer-like valve, accepts a needle or male Luer for administration of fluid (frequently, this is done with a syringe). Intravenous catheters may be in for only minutes in places like an outpatient clinic or they can be in for years in a situation such as subcutaneous indwelling port access devices. There may be dozens or thousands of access events per intravascular device; each connection and access step has the potential to be a deadly one.
One of the problems with the current international ISO standard for Luer connectors is that Luer slip connectors are left with their tip-mating surface exposed. The slip connector's surface goes directly into the intravascular lumen. Luer connectors with locking collars have some degree of proximal contact contamination protection; however, even Luer connectors with locking collars have a high risk of contact contamination due to the 2.1 millimeter (mm) protrusion of the male tip beyond the collar of dictated by the current ISO standard; this makes the tip prone to contamination by contact with non-sterile surfaces (this can happen in a number of ways).
For example, the tip of intravenous tubing may be contaminated while exposed and resting on a stretcher-sheet surface. The torque of the IV tubing may cause the connector tip to touch the non-sterile linen and become contaminated. The longer the tip extends beyond the collar, the more risk there is of contamination, since there is less of an angle needed to change from a non-contaminated state in a orientation parallel to a flat sheet surface, to an angled state where the tip contacts the sheet. In contrast, the shorter the distance that the tip extends beyond the Luer locking collar, the less likely that such as event would occur.
Another risk of contamination occurs while handling the connector as the connector might be pushed into a non-sterile surface. For example, the sterile connector tip might be pushed into a bulge in the stretcher sheet or another device. If the protrusion distance of the tip from the collar were less than zero, the tip will be recessed within the collar. A tip recessed in a collar would have less chance of contamination since the collar would shield contact between a non sterile surface and the sterile tip of the male Luer.
Yet another potential contaminated surface is a finger or a glove of the health care provider. These surfaces might inadvertently touch the connector tip causing contamination. Sometimes this will occur when handling the connector for assembly, capping or recapping. The more deeply recessed the tip within a shielded collar, the less likely such an event will occur since the intruding non-sterile surface would have to travel farther within the collar to make the contact to contaminate the tip. Contact with the tip is an important factor since the tip will go directly into the fluid path while the collar remains on the outside.
There are other situations during the assembly process that make the standard Luer connectors prone to contamination. The male Luer connectors have a small tip that must engage a small female receiving end; sometimes, this can be difficult to achieve in a moving, uncooperative patient. Also, if the healthcare worker's vision or depth perception is poor, they are more likely to miss their target. In some cases, the protruding male connector tip might miss the female connector altogether. For example, the tip of the connector might hit a finger stabilizing the female connector. It might hit the side surface of the female connector which may not have been sterilized prior to access. If the male connector is then immediately inserted into the female connector, without re-sterilization, contamination may occur. Even if attempts are made to clean the male connector tip surface with a disinfectant, such as an iodine containing solution or alcohol, the residual disinfectant may have harmful toxic effects, or the practitioner may not wait for necessary drying to occur and contaminants may be flushed directly into the bloodstream once the male connector is connected and an infusion begun.
Recent advances in the medical connector field have focused on needleless access to reduce the risk of needle-sticks during the administration and disposal of needles used with injection ports. Needle-sticks can transmit deadly incurable infections to healthcare workers including HIV and Hepatitis. Since female connectors are standard for the input end of intravenous lines, the needle-stick reduction innovations have focused on improving the female input end. This is presumably because the output end had been needles attached to Luer lock syringes and when the needles are removed what remains is the male end of a universal fitting standard male Luer lock adapter.
While these medical connector designs have improved the safety conditions for healthcare workers by reducing needle-stick risks, they have brought on new issues related to safety of the patient being treated. For example, some of the new needleless access systems comprise valved features that increase the risk of bloodstream contamination due to the irregular surface contours that are more difficult to clean than a smooth surface. Some connectors have larger, wider connector bodies to accommodate the inner valve contents. These valve bodies can be wider than a standard female Luer stem. These wide connector bodies can be bigger targets for potential contact contamination of standard male Luer tips at the time of assembly and access, since typically only the proximal female connector end port is swabbed clean at the time of access and not the entire connector body which is frequently stabilized by non-sterile hands or gloves or has been in contact with the nonsterile skin surface of the patient. These wide bodied connectors reduce the margin for error since the male Luer tip might miss the female access port and instead of moving freely into the air, it will be more likely to hit the wide valve surface in close proximity that is contaminated.
Also, some of these needleless valve female connectors may accept male Luer connectors but do not have the standard female Luer dimensions. Some have a shortened distance from the female inlet end to the connector base. The outer surface of the wide bodied connector is closer to the female access end; therefore accelerating the tip touch contamination risks by reducing the margin for error when making connections at the female valve inlet.
Furthermore, another patient safety issue is that some of the newer needleless valve systems have new issues related to bounce contamination. These systems may have a flat or relatively flat receiving surface compared to the standard inner conical receiving surface of a standard female Luer lock. Downward pressure is required to activate these new needleless valves. Problems occur because the tip of a standard male Luer locking connector may touch the female connector end receiving surface before stabilization and engagement of the locking collar. A number of problems may result. The tip of the male connector may slide from a sterilized top surface to a non-sterile side surface. Even if the target is correctly contacted initially, the resilience of the valve may cause a “bounceback” effect pushing the male tip off the surface and then bouncing onto another non-sterile surface. The valve must be depressed the standard protrusion distance of the male Luer tip past the collar of 2.1 mm, before the standard Luer locking collar assists with stabilization.